I tested my application changes with both JUnit and within JDeveloper and
everything works fine. However, am I unable to deploy the application EAR
file to an OC4J container. I followed the instructions in the web tutorial:

I tried Option 1 which is the recommended option where I substituted the
eclipselink.jar file for the toplink-essentials.jar file in the
$OC4J_HOME/config/server.xml. After making the change and attempting to
deploy my EAR file, I now get the following error in the OPMN log file:

It appears that the TopLink Essentials EntityManagerFactory is being used
instead of the EclipseLink EntityManagerFactory.

I got the same error when trying Option #2. I am deploying the application
to a separate application server called "BRTK" than the default "home" so
I'm not sure if that is the cause of the error. My OC4J home is
/j2ee/BRTK/. I have this setup because I need to support multiple
applications and the legacy apps in the other app servers may still be
using TopLink Essentials. I only modified the files in the "BRTK" app
server.

Yvon,
Hi, verify that your persistence-unit provider is explicitly set to
org.eclipse.persistence.jpa.PersistenceProvider. It may have defaulted to
essentials in the past if left out as is the case on GlassFish with
TopLink Essentials.